What does life expectancy measure?
the average income a population likely earns during employment
the average human development during a population's lifetime
the average number of years that a population is likely to live
the average standard of living during a population's lifetime

Life expectancy measures the average number of years that a population is likely to live.

Explanation:

Life expectancy is the average life expectancy of all persons in a geographical area or a population group. The average age is calculated by summing the age of all who die within a year and dividing the number by the number of deaths. In America, for example, life expectancy is 78.6 years.

Life expectancy has increased globally in the 20th century as a result of the medical revolution. Various medical developments mainly explain the rise in life expectancy to the present level, but have also been influenced, for example, by the availability and quality of food.

the process is called revolution because it was a process of great economic-social transformations that began in england in the xviii century.

the industrial mode of production spread throughout much of the northern hemisphere throughout the xix and early xx centuries.

the effect of this revolution was the distance between the countries, with respect to economic and political power.   after all, not all industrialized at the same time, remaining in the condition of suppliers of raw materials and agricultural products to the industrialized countries.

these differences mark to this day the nations of the world that are divided between developed and developing countries. one way to measure whether a country is advanced is to assess how industrialized it is.

the hebrew bible is the sacred text of judaism;

the koran is that of islam.

among eastern religions, the sacred scriptures of hinduis are the four vedas and the upanishads, among others.

a main characteristic in these books is that un most of them we find certain "norms" of behavior, as is the case of the bible that has it's commandments. these rules are to regulate the behavior of believers and faithful of their respective faith.

these rules tell us what is right and what is not.